//C++ header - Open Scene Graph - Copyright (C) 1998-2001 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.

#ifndef OSG_SHADOWOCCLUDERVOLUME
#define OSG_SHADOWOCCLUDERVOLUME 1

#include <osg/ref_ptr>
#include <osg/ClippingVolume>
#include <osg/ConvexPlanerOccluder>

namespace osg {

/** ShadowOccluderVolume is a helper class for implementating shadow occlusion culling. */
class SG_EXPORT ShadowOccluderVolume : public Referenced
{

    public:
    
    
        ShadowOccluderVolume(const ShadowOccluderVolume& soc,Matrix& MVP);
        
        ShadowOccluderVolume(const ConvexPlanerOccluder& occluder,Matrix& MVP);

        typedef std::vector<ClippingVolume> ClippingHoleList;
        
        /** Convert shadow occluder into local coords by multiplying the
          * clip space occluder by the ModelViewProjectionMatrix.*/
        void set(const ShadowOccluderVolume& soc,Matrix& MVP);

        /** Initialize a ShadowOccluderVolume to a ConvexPlanerOccluder 
          * transformed into clipspace.*/
        void set(const ConvexPlanerOccluder& occluder,Matrix& MVP);
        
        /** return true if the specified bounding sphere is contaned entirely
          * within this shadow occluder volume.*/
        bool contains(const BoundingSphere& bs);
        
        /** return true if the specified bounding box is contained entirely
          * within this shadow occluder volume.*/
        bool contains(const BoundingBox& bs);
        


    protected:
    
        // the original shadow occluder computed in clip space
        ref_ptr<ShadowOccluderVolume>   _clipSpaceOccluder;

        ClippingVolume                  _occluderVolume;
        ClippingHoleList                _clippingHoleList;
};

}	// end of namespace

#endif